In Defense of the Exclusionary Rule

by Timothy Lynch

Timothy Lynch is associate director of the Cato Institute's Center for Constitutional Studies.

Executive Summary

The Fourth Amendment to the U.S. Constitution protects Americans against unreasonable searches and seizures by government officials. Like other guarantees in the Bill of Rights, however, the Fourth Amendment cannot enforce itself.

Much of the modern debate about the enforcement of the Fourth Amendment has focused on the wisdom of and constitutional necessity for the so-called exclusionary rule, under which evidence obtained in violation of the Fourth Amendment is ordinarily inadmissible in a criminal trial. Conservatives often oppose the rule as not grounded in the Constitution, not a deterrent to police misconduct, and not helpful in the search for truth. Abolishing the exclusionary rule has been a high priority for conservatives for more than 30 years. When Republicans gained control of Congress in 1995, they immediately set their sights on the exclusionary rule. Although that "reform" effort did not succeed, it is likely that similar efforts may resurface.

The drive to abolish the exclusionary rule is fundamentally misguided, on constitutional grounds, for the rule can and should be justified on separation-of-powers principles, which conservatives generally support. When agents of the executive branch (the police) disregard the terms of search warrants, or attempt to bypass the warrant-issuing process altogether, the judicial branch can and should respond by "checking" such misbehavior. The most opportune time to check such unconstitutional behavior is when prosecutors attempt to introduce illegally seized evidence in court. Because the exclusionary rule is the only effective tool the judiciary has for preserving the integrity of its warrant-issuing authority, any legislative attempt to abrogate the rule should be declared null and void by the Supreme Court.